Apparatus for extruding metals.



PATENTED MAR. 1.3, 1:206.

N. A. ROBERTSON. APPARATUS FOR EXTRUDING METALS.

APPLICATION FILED JAN.27, 1905.

3 SHEETS-SHEET 1.

INVENTOR:

I By Aliameys,

WITNESSES: 7&4 W

No. 814,731. PATENTED MAR. 13, 1906.

N. A. ROBERTSON. APPARATUS FOR EXTRUDING METALS.

APPLICATION PIIQEITJAN. 27, 1905.

' 3 SHEETS-SHEET 2.

FIG; 4.

FIG. 3. J

v 'INVENTOR:

WITNESSES;

W By A lzorneyj,

m .O wr M the principal SON, a citizen of the UNITED STATES PATENT OFFICE.

NoRM'AN A. ROB

ERTSON, OF NEW YORK, N'.;Y.

APPARATUS FOR EXTRUDING METALS.

To all whom it may concern.

Be it known that I, NORMAN A. ROBERT- United States, residing in the borough of Brookl county of Kings, city and State of New rk, have invented certain new and useful'Improvements in A paratus for Extruding Metals, of which tl ie ollowing is a specification.

This invention relates to an improved machine for extruding metal-that is to say, forcing it through a die, either in a solid or hollow wire or upon a core-wire of other material.

The improved machine is specially designed for extruding aluminium or other metals which require an extreme pressure and generally a high temperature.

Machines for extruding lead and other soft metals are well known; but these are not adapted to the particular work for .which the present machine is designed for reasons which are stated in detail hereinafter.

An im ortant feature of the present machine is the introduction of the metal in se arate streams, the passages leading to the iechamber being unconnected back of said chamber, and the arrangement of the passa es a considerable distance apart from each other and from the core between them, so as to provide a heavy wall around the core capable of resisting extreme pressures at high emperatures.

A second feature of advantage is the construction of the machine whereb the core, though extending in the general irection of the passages, is exposed only at its end to the pressure of the material.

Certain other features are referred to in detail hereinafter.

The accompanying drawings illustrate embodiinents of the invention.

Figure 1 is a section through the center of arts of the machine, being taken in two planes on the line 1 1 of Fi 2. Fig. 2 is a top plan of the part or block w ich carries the cylinders. Fig. 3 is an under side plan of the part or block which contains the converging passages leading to the die-cham her. Fig. 4 is a top plan of the third part or block which forms the bottom of the diechamber and carries the die. Fig. 5 is, a fragmentary section on the line 5 5 of Fig. 3, but omitting the upper block and the core. Figs. 6 and 7 are respectively a side elevation and under side plan view of a multiple core. Fig. 8 is a vertlcal section of the complete ma- Speciflcation of Letters Patent. Application filed January 27,1905. Serial No. 242,937.

blows out Yatented m i en 1a, 1906.

chine with certain parts in elevation. Fig. 9 is a horizontal section of abloc'k carr' gcom ensating cylinders, hereinafter escribed. ig. 10 is a section illustratinganother method of holding down the core of the machine. Fig. 11 is an elevation of a plug for replacing the core. Figs. 12 and 13 are cross-sections of alternative products.

The machine is preferably arranged vertically, as indicated, though it ma operate in a horizontal direction as well. 'l he machine is also shown with a core which may be used to form a hollow or tubular product or to.

carry a core-wire'of the product; but in connection with some of the-features claimed the core of the machine may be omitted to'form a solid wire of aluminium or the like. Certain features are, however, applicable especially to a machine having a core.

In the extrusion of aluminium I have observed that if the metal be somewhat liquid it spurts or blows out through the die. As

it cools below the point of liquidity it becomes more or less granular or crystalline in consistency, and at this stage also the metal instead of being squeezed out in a constant stream. This blowing outis thought to be due to the gases sorbs in large quantities while molten. It is therefore necessary to extrude the aluminium at a temperature below its granular stage when it has become so hard as to prevent spurting. This temperature necessitates maintaining the die and the core of the machine (where such a core is used) at or preferably just below a dull-red heat: ness of the aluminium, further, necessitates extraordinar ressure. Und'erthese circurn stances it will e apparent that the metal of the machine itself is of much less'str'ength than .when cold. The machine has therefore been designed to have the greatest strength and to protect the parts, and es ecially the core, as much as possible from t e extreme pressure and to arrange them so-as to resist as well as possible the ressure which they receive. Also the maciiine is arranged to which aluminium 'ab-' The stiff-' force the metal as nearly as possible inthe same eneral direction (which Ihave called the longitudinal direction) from theentrance to the exit of the machine, so as to re- I duce as low as possible the amount of respassa these assages being extended backward to the en of the machine-that is, upward to the top with the vertical arrangement shown through longitudinal cylinders O, which are preferably unconnected with each other. The term assa e is used 1n its generic sense to inciiide t e cylinders in which the plungers reciprocate, as well as the oblique es or conduits A, and to include the combination of a conduit A and the cylinder which forms a continuation thereof. Thus the metal is introduced in separate streams from separate cylinders instead of from one cylinder through passages which divide or branch to separate the metal into two streams beforeleading it to the die-chamber, as is common in' lead-extruding machines. By my new construction the machine is greatly strengthened.

The cylinders C are formed in a portion or block D of the machine separate from the portion or block E which has the converging passages A. The cylinders are widely separated from each other, so as to leave a heavy wall of material between them and-wi thin the center surrounding the passage F, through which a core-wire is to be passed. Hence even though the material be red-hot and the walls of the several passages be thus weakened, et there can be no collapsing of the centrai wall surrounding the passage F.

The use of two separate blocks D and E enables me to use a short core G, extending u ward only to the u per face of the block This. core is abun antly protected by the thickness of the material of the block E, which surrounds it. Fig. 3 shows that the core is surrounded by three wedge-shaped portions of the block extending between the passages and from the core to the outer circumference, where the heat is generally applied. The u per end of the core G is formed with a collar which fits in a suitable socket in the top of the block E. The block D rests upon the upper end of the core G to hold the latter down. In order to'avoid the strain which this construction brings on the rods holding the blocks D and E together, the core G Fig. 10, may be held down by a nut G screwin into a socket in the u per face of the bloc At the upper end 0 each of the passages A there is an upwardly-projecting oss J, fitting into the bottom of the corresponding cylinder C to determine the ositron of the upper block on the bloc E. Where a core-wire K is to be coated with the external material, the core G of the machine is provided with a central assage in line with the passage F. Where ho low tubin is to be formed, however, the passage F may e omitted and the core G of the machine may be made solid, and where a solid extruded bar or wire is to be formed the core G of the machine may be omitted, the block E being solid except for the converging passages A and the chamber in which they meet, or, to like effect the core G may be replaced 'by a solid plug G". (Shown in Fig. 11.)

A lower block L forms the bottom of the die-chamber B and in connection with the block E constitutes the part of the machine analogous to what is .generally known as the die-block. D, E, and L, however, as the upper, intermediate, and lower blocks for the sake of clearness. The lower block L carries the die M, which is held up on the end of a hollow screw N. Above the die M the block is more or less recessed to guide the material properly to the constricted mouth 0 of the die.

The lower end of the core G of the machine projects more or less into the die-chamber and generally into the mouth of the die to determine the amount of material assing through the die. With the use of suc a stiff material as aluminium and under the severe conditions described it is essential to make the core as strong and to sup ort it as strongly as possible a ainst side tiirust. This side thrust is liab e to occur from a variety of causes, as the greater liquidity of the metal in one of the cylinders C and passages A or the greater friction in one of said cylinders and passages, whereby the pressure from the o osite side would be more ell'ective and would bend the end of the core and destroy the regularity of the product. With an even number of passages A converging upon the core it is apparent that a reduction of pressure in one would tend to cause the bending of the core by reason of the preponderance of pressure in the passage diametrically opposite. The only resistance to the pressure from one passage would be furnished by the pressure in the passage diametrically opposite. I propose, therefore, to provide an oddnumbered plurality o1 passages A, preferably three, asshown, and in lanes equiangularly placed relatively to eac other, so that the ressure from each passage upon the core will e opposed by the solid metal of the block E, which extends down in a point P diametrically opposite each passage A. This point P of metal is best indicated in Figs. 3 and 5.

The machine-core may be formed as at G in Figs. 6 and 7, having a plurality of central passages for carrying wires to form the cores of the roduct 01' be embedded in the product. his multiple core G maybe used with a series of separate dies, so as to form at once several separate wires, or it may be used with a single die to form a product in which a plurality of core-wires are embedded.

In operation, assuming that a wire of alu-' minium with a steel core-wire is to be made, the steel Wire K is run through the core and die in the usual way. The passages A and cylinders C are then filled with aluminium, molten or in the form of slugs or otherwise. If introduced molten, it is allowed to cool to I have designated the parts plunger R, and the aluminium is forced down' through the converging passages A. In the chamber B the streams coalesce and thence pass out around the core of the machine throu h the die, carrying with them the corewire 1%. When the desired amount of aluminium has been extruded, the plunger R is forced down, carrying with it the three blocks D, E, and L, it being connected to the ripper block D by means of bolts S and a ring An open stool U is interposed between the lower block L of the apparatus and the top of the plunger R to permit the withdrawal of the complete product V laterally.

In order to insure an equal filling oi the cylinders C, there is preferably provided a shallow trough W, Fig. 2, connecting the upper open ends of the cylinders, (though these cylinders are entirely unconnected after the operation has commenced.) The purpose of this trough is to insure that all the plungers Q shall come to a bearing on the metal in their several cylinders at the same time, so that the metal shall not be forced through one of the passages A before it commences to How through the others. With the trough W the entry of the plungers Q into the cylinders A at first forces out metal into the trough W, and until each of the plungers has passed below the trough W this trough forms a sort of safetyvalve or overflow to prevent extreme pressure by any one of the lungers.

Another construction w ich may be used with or without the trough W and which is designed to brin the several plungers Q to an even bearing be ore commencin the extruding operation is illustrated in igs. 8 and 9. The plungers Q are supported at their upper ends in cylinders which are connected with each other and arranged to be supplied with oil or other liquid, the several cylinders being in communication with each other, so that if one lunger engages the metal to be ex truded hefore the others the reaction from the first plunger will force down the others and all the plungers will come to an even bearing and begin the extruding operation at the same time. For this purpose the head X of the machine may be provided on its under side with a casting Y, in which are formed three cylinders Z, connected at their upper ends by passages a and connected to a pipe (5, through which liquid may be admitted or discharged The metal to be extruded'is maintained at the desired temperature by heating the apparatus from the outside. For example, a serles of gas-blow pipes 1' may be arranged around the lower and intermediate blocks L and E and another series of similar blowpiries around the up er block D.

igs. 12 and 13 ilustrate wires V and V of respectively circular and trefoil shape in cross-section, which may be made with a plurality of core-wires K by the use of the core G and dies corresponding to the contours of the sections shown.

Though I have described with great particularity of detail certain apparatus embodying the invention, yet it is not to be understood therefrom that the invention is limited to the specific embodiments disclosed. Va-

rious modifications. thereof in detail and in the arrangement and combination of the parts may be made by those skilled in the art Without departure from the invention.

What I claim is. 1. An extruding machine comprising a block having a lurality of separate cylinders, and a second b ock having corresponding inclined passages leading from said cylinders to the die-chamber.

2. An extruding machine comprising a block having a lurality of separate cylinders, a second block h passages leading from said cylinders to the die-chamber, said passages and cylinders being spaced apart a considerable distance from each other whereby a heavy wall is provided between them capable of resisting extreme pressures at high temperatures.

3. An extrudingmachine comprising a block having a lurality of separate cylinders, a second block having corresponding inclined passages leading from said cylinders to the die-chamber, said passages and cylinders being spaced apart a considerable distance from each other, and a core arranged between said passages, with a heavy wall between said passages and said core capable of resisting extreme pressures at high temperatures.

4. An extruding-machine comprising an upper and a lower block and having a plurality of passages leading vertically through said u per block and obliquely through said lower lock to the die chamber, and a core carried in the lower block and projecting into said chamber.

5. An extruding machine having a diechamber, a plurality of passages converging into said chamber, and cylinders extending longitudinally, unconnected with each other, leading into said passages and formed separately from the portion of the machine having said passages.

6. A vertical extruding-machine having a lower block' carrying a vertical die and forming the bottom of the diechamber, an intermediate block forming the top of said chamber and having converging passages leading to said chamber, and an upper block fitting on top of saidintermediate block and through which said passages are extended in a longitudinal direction to the top.

aving corresponding inclined 7. An extruding-machine having one part in which are passages leading to a die-chamber, a second art separate from the first and through whicli the material is conducted to 5 said passages, acore carried by said first-mentioned part and lying between said passages so that they converge toward it, and means for forcing material through all of said passages simultaneously so that the pressures on 10 the core from said passages balance each other. 7

8. An extruding machine having a block E in which are converging assa es A leading to a die-chamber, a second bloc D separate [5 from the first and in which are formed cylinders C connecting with the ends of the passages A, a core carried by saidfirst-mentioned block and lying between said passages A so that they converge toward it, and means for forcing material through all of said passages :0

simultaneously so that the pressures on the corefrom said passages balance each other.

9. An extruding-machine having an end block in which is a die, an intermediate block in which is a core, and an op osite end block 2 5 in which is a cylinder for con ucting material to the die-chamber, the intermediate block being confined between the two end blocks.

In witness whereof I have hereunto si ned my name in the presence of two subscri ing 3 witnesses.

NORMAN' A. ROBERTSON.

Witnesses DOMINGO A. USINA, THEODORE T. SNELL. 

